Method of producing homogeneous bodies from tantalum or other highly-refractory metals.



No. 873,958- PATENTED DEGflV, 190'7.

' M. VON PIRANI. METHOD OF PRODUCING HOMOGENEOUS BODIES FROM TANTALUM OR OTHER HIGHLY REFRACTORY METALS.

APPLICATION rum) MAR. 18, 1907.

I [Mal/6720 d I mm'a ' UNITED S ATEs-PA ENT. OFFICE,"

. :MARGELLO VON PIRANLOFWILMERSDORF, NEAR BERLIN, GERMANY, ssieNon TO SIEMENS & HALSKE AKTIENGESELLSGHAFT, or BERLIN, GERMANY, A c RPORATION or GER- MANY.

REFRAQTORY METALS.

Specification. of Letters Patent. 7

' PatentedD ec'.'17,1907.

' Applicatioii filed March 18= 1907. Serial N6. 362.821.

To all whom 'it may concern:

Be it known that I, MARCELLO YON PIRANI, a subject of the King of Italy, and

resident of Wilmersdorf,.near Berlin, Ger

many, haveinvented a certain new and useful Improvement in a Method of Producing Homogeneous Bodies from Tantalum made from the metallic powder by compresor other Highly-Refractory Metals, of which the following is a specification.

The present invention relates to a method of producing homogeneous bodies from tantalum or other highly refractory metals.

Exceedingly coherent bodies are first sion conglobation or concretion, saidbodies then serving as positive electrodes in the combustion furnace; a metallic oxid which emits ions when heated is arranged in the furnace in connection with the cathode, for the purpose of facilitating the passage of the current between the electrodes even with a very high vacuum.

The production of homogeneous bodies from tantalum or other highly refractory metals has hitherto been efiected by ex- 7 'ceedingly solid bodies being made by compression or concretion from the metallic powder which was employed as the starting material. These bodies were heated to their melting point in an indifferent atmosphere between two electrodes by the electric current. The melting operation necessitated sult is obtained by the residue of gas which I a relatively small expenditure of energy when the body which was to be melteri was itself employedas a positive electrode in the formation of the arc formed by the current. With a very high vacuum, however, the arc passes with difiiculty between the electrodes.

remains in the vacuum furnace being ionized; The ionization-is effected by a metallic oxid being placed in the furnace and heated. The oxid is preferably connected. withthe cathode, and the heating is most simply effected by means of a wire of platihum, tantalum, or the like which is embedded in theoxld and which is caused to glow by the passage of an electric current through the same. Barium oxid is particularly suitable for the ionization; further, strontium oxid, calcium oxid, or magnesium oXid, or other 0X1(lS may also be employed.

In order that the Invention may be more clearly understood, reference is made to the I accompanying drawing in which apparatus suitable for carrying the method into effect is shown by way of example diagrammatically in Figures 1 and 2.

Similar letters of reference refer to similar parts in both views.

. In the figures, a indicates the body which is to be melted. V

1) represents the oxid and d the evacuated vessel or furnace in which the melting is to be efi"ected. The oxid is heated by a wire which is connected to a source of current 0 and which is embedded in the voXid. The same wire may be simultaneously connected to the cathode of the source of current which is employed for melting the body a and which is used for forming the arc, whereas the body a which is to be melted is joined to the' anode of the latter source of current. As .soon as the oXid is sufliciently heated, which is the case at about red heat when employing barium oXid, the arc passes-spontaneously between a and b Even'with a considerable distance between the anode and cathode, very considerable currents can be sent through the ionized vacuum chamber. For

example, with an interval between the electrodes of several centimeters and at the tension of about 100 volts, an arc of 50 amperes and more may be produced by means of which the body a is easily melted.

The current'may be regulated in a twofold manner; namely, on the one hand by regulating the temperature of the oxid, and on the other hand by regulating the strength of the current bymeans of a variable rheostat e in the main circuit. 1

An arrangement is represented in Fig. 2 in which a three wire systemis employed. The current regulator e is located in the positive outer conductorwhich leads to the body a which is to be melted. The heating resistance in the oXid b is situated between the neutral conductor and the negative outer conductor, and in the neutral conductor is also a variableresistance f which is used for regulating the -tem erature of the oxid. The current asses etween the two outer conductors t ough the ionized vacuum. Even if continuous current is preferably employed in executing the method in accordance with the present invention, it is also'possible to employ alternatin current i whereby similar effects are obtaina 1e.

What I claim as my invention and desire to secure by Letters Patent is;

1. The method of producing homogeneous bodies from tantalum and other highly m fractory metals which consists in creatmg a substantial vacuum, ionizin the residue of gas therein and subjecting t e metal to the influence of an electric arc therein.

2, The method of producing homogeneous bodies from tantalum and other highly refractory metals, which consists in creating a substantial vacuum, ionizing the residue of gas therein, and forming therein an electric are from the metal.

"3. The method of producing homogeneous bodies from tantalum and other highly refractory metals, which consists in creating a substantial vacuum, ionizing the residue of gas therein, connecting the metal with the anode of an electric arc circuit therein and passing anelectric current through said circult.

4. The method of producinghomogeneous bodies from tantalum and other highly refractory metals, which consists in creating a substantial vacuum, heating a-metallic oxid therein and thereby ionizing the residue of gas therein, and subjecting the metal to the mfluence of an electric arc-therein.

5. The method of producing homogeneous bodies fromtant'alum and other highly refractory metals, which consists in creating a substantial vacuum, heating a metallic oxid therein and thereby ionizing the residue of gas therein, and forming therein an electric are from the metal. i

6. The herein described process of producing homo eneous bodies from tantalum and ot er hig ly refractory metals, whichconsists in creating a substantial vacuum, heating a metallic oxid therein, and thereby ionizing the residue of gas therein, connecting the metal with the anodeof an electric arc circuit and passing an electric current through said circuit.

7. The method of producing homogeneous bodies from tantalum and other highly refractory metals which consists in creating a substantial vacuum, electrically heating a.

metallic oxid therein and thereby ionizing the residue ofgas therein, and sub'ecting the metal to the influence of an electric arc therein.

' metallic oxid therein,I and thereby ionizing current throughsaid circuit.

' factory metalsywhich consists in creatlng a substantial vacuum, electrically heating a the residue, of gas t erein,' connecting the metal withthe anode of an electric arc clrcuit inisaid vacuum and passing an electric 10. The methodof roducing homogene' ous bodies from tanta um and other lughly refractory metals which consists in creating a substantial vacuum, passing an electric current through aconductor embedded in a metallic oxid therein, and thereby ionizing the residue of gas therein, and subjecting the metal to the influence of an electric arctherein.

11. The method of roducing homogeneous bodies from tantal im and other highly refractory metals which consists in creating a substantial vacuum, passing an electric current through a conductor embedded in a metallicoxid therein, and thereby ionizing the residue of gas therein, and forming therein an electric are from the metal.

12. The method of roducing homogeneous bodies from tantaliim and other highly refractory metals, which consists in creating a substantial vacuum passing an electric 100 current through a conductor embedded in a metallic oxid therein, and thereby ionizing the residueof therein, connectin the metal-with the anode of aneleotric arc clrcuit therein, and assing an electric current through said e ectric arc circuit.- v

13. The method 'of roducing homogeneous bodies from tanta um and other highly refractory metals which consists in creating a substantialvacuum,connectin a'metallic 11-0 oxid therein with the cathode 0 an electric arc circuit therein, passin .an electric current through a conductor em added the said metallic oxid, and thereby ionizing the residue of gas in said substantial vacuum, connecting the metal with the anode of said electric arc circuit and passing an electric current through said electric arc circuit,

In testimony whereof I have signed my name to this specification in the-presence of 120 the two subscribing witnesses.

MARCELLO VON PIRANL 

